I configured the By-me control board some time ago without a burglar alarm line and now I have to add one. Is it possible?

If the control unit is initialized with an Area and Line address that is not Area00/Line00, you have to reset the control unit and all devices already configured.in order to add the SAI burglar alarm line. The system is therefore completely reconfigured by initializing the By-me control unit with Area 00 and Line 00, the same is then connected on the intrusion system line and will require the addition of an 01845 line coupler to generate the light line Area01/Line00.